People have been talking about the fact that the two participants in this America's Cup seem to be constantly improving. Well, that is because the AC Rules work in a way that let the teams tweak their boats so they can continue to change, develop and still measure in. New measurement certificates are handed in almost daily. Tweaks overnight aren't just for maintenance, but for speed. As long as the teams stay within the parameters of the AC Rule (maximums and minimums), they are good to go!

For sure both boats are at the very top of the weight range allowed by the AC Rule. I believe there are only about 250 kilograms between the AC Rule maximum and minimum weight, so there's not a lot in it. I know that ETNZ has a little weight to spare and that OTUSA is right at the limit. That is prior to taking about 1/3 of their bow sprit off yesterday, which should buy them a little room with weight.

The reasons that both Emirates Team New Zealand and Oracle Team USA are at the top of the weight limit is two-fold. First, the boats are way overpowered and the designers don't think that the little bit of weight makes any difference. And second, they get to put more aerodynamic fairings in place which produce efficiencies that far outweigh the extra pounds added.

This continuous development onboard both boats is why they seem to be quicker day-to-day. And don't look for this to change until the final gun is fired.

Tune in today at 4pm ET on NBC Sports Network to watch races 9 & 10. Should be a very exciting race with the score now ETNZ-6, OTUSA-0.
All America's Cup broadcasts will air live on ESPN3 (web-based ESPN), with Todd Harris and yours truly making the calls. We will also welcome a guest commentator to the panel and let them tell the story from an entirely different perspective. Stay tuned.